https://www.facebook.com/reel/1817299472352574/?mibextid=9drbnH&s=yWDuG2&fs=e
Archive for the ‘Do It Yourself’ Category:
2024-08-31 AM Transmitter, Low Power
This is an AM transmitter that this guy built. He says it’s rich in harmonics – it has no tuning nor low pass filtering and the stages are class C, no forward bias. It should have all the things used to minimize harmonics, like a low pass filter. Class C operation is used to maximize
(Read More…)
2024-08-21 Adjustable Power Supply Uses Sziklai Pair
This messy bunch of parts is a 0 to 9V adjustable power supply. The original power supply board connected the two transistors in the Darlington Configuration. The unregulated 12V input goes through a 187 ohm resistor to a 10V zener diode to give a stable reference voltage. This voltage is fed to a 2.5k linear
(Read More…)
2024-05-29 Solar Panel Controller To Charge Lead-Acid Battery
This is a simple charge controller that includes a dump load to dissipate excess power from the PV panel. D1 is the reference voltage that feed the 393 comparators, and its forward voltage changes with temperature. It would be better to use a low power LM317 to give a stable 1.25 volts. Instead of a
(Read More…)
2024-05-13 Autonomous Solar Tracking System
For each direction of travel, it consists of two solar cells connected in parallel opposing to a motor that’s geared down to turn the tracking so both solar cells are in the shade. https://www.facebook.com/reel/7341922389263306?mibextid=9drbnH&s=yWDuG2&fs=e
2024-04-20 RCWL-0516 Microwave Doppler Motion Sensor Module Schematic KO4BB
The modules use both the RCWL-9616 and the BISS-0001 but it seems the schematics are all labeled BISS-0001. The parts values are different. He gives some good information about them. They operate at 3.5 and 3.98 GHz – the ones I have were advertised at 5 GHz. Also he shows his own version that uses a
(Read More…)
2024-04-16 White Vinegar Isn’t Neutralizing NiCad Electrolyte
I put white vinegar on the areas where the NiCad juice turned the PCB green, and it didn’t seem to do anything. So after awhile I washed it off with plain tapwater. I used a soft brush and a lot of the green coating washed off. It’s not in very good shape. I’m wondering if
(Read More…)
2024-04-10 FM Regenerative Receiver Using MPF102 JFET
A basic one transistor regen receiver uses an MPF102 JFET to give the regenerative gain. Also uses two transistors to amplify the audio to drive an earphone. https://www.circuitbasics.com/what-are-fm-receivers/
